"And something that we could do on the bias, which is a cornerstone to his creative voice." As McGregor's Halston prepares for what would be his breakout runway show, assistant Joel (Rory Culkin) brings in a blue fabric tie dyed with an abstract floral pattern - "it's my design, as Halston," says San Juan of the graphics - conveniently set in the center where a hole for the head could be cut. "I really wanted to celebrate the caftan because it's what's synonymous with Halston," she says, noting that she chose vibrant hues to stand out from the show's replica of Halston's earlier Moroccan souk-inspired Madison Avenue showroom, which was designed by friend Angelo Donghia in 1967. San Juan also pitched a scripted moment, seen in the first episode, to help demonstrate Halston's famed design technique, which involved diagonally slicing a piece of fabric, straight from the bolt, to drape and design a languid silhouette directly onto one of his models. Halston cuts, drapes and pins a caftan on Elsa. For this project, she "absorbed everything" through expansive research, which included personally talking to the real Halston's inner circle - from head tailor Gino Balsamo and assistant Sassy Johnson to Halstonette Chris Royer - for first-hand accounts and even garment loans, to be able to break down the science behind the designer's distinctive methodology. "Initially, it felt like a heavy baton to be handed," says Jeriana San Juan, the costume designer behind the Netflix miniseries "Halston," based on the book "Simply Halston" by Steven Gaines, starring Ewan McGregor and executive produced (and co-written) by Ryan Murphy. She last visited the '70s in " The Get Down" (and the pre-war era in "The Plot Against America"). designer Elsa Peretti and a diverse group of models dubbed the Halstonettes. Not only did Roy Halston Frowick change the face of American fashion and redefine how women dress, he also established an iconic aesthetic for himself and his game-changing muses, which included Liza Minelli, future Tiffany & Co.